biofilm was inhibited by tryptanthrin through disrupting its different stages and genes expression.

Biofilm formation plays a significant role in antibiotic resistance, necessitating the search for alternative therapies against biofilm-associated infections. This study demonstrates that 20 μg/mL tryptanthrin can hinder biofilm formation above 50% in various strains. Tryptanthrin impacts various stages of biofilm formation, including the inhibition of surface motility and eDNA release in , as well as an increase in its sensitivity to H0. RT-qPCR analysis reveals that tryptanthrin significantly decreases the expression of the following genes: abaI (19.07%), abaR (33.47%), bfmR (43.41%), csuA/B (64.16%), csuE (50.20%), ompA (67.93%), and katE (72.53%), which are related to biofilm formation and quorum sensing. Furthermore, tryptanthrin is relatively safe and can reduce the virulence of in a infection model. Overall, our study demonstrates the potential of tryptanthrin in controlling biofilm formation and virulence of by disrupting different stages of biofilm formation and intercellular signaling communication.